Problem: Khan.scratchpad.disable(); Gabriela sells magazine subscriptions and earns $$7$ for every new subscriber she signs up. Gabriela also earns a $$21$ weekly bonus regardless of how many magazine subscriptions she sells. If Gabriela wants to earn at least $$82$ this week, what is the minimum number of subscriptions she needs to sell?
Answer: To solve this, let's set up an expression to show how much money Gabriela will make. Amount earned this week $=$ $ $ Subscriptions sold $\times$ Price per subscription $+$ Weekly bonus Since Gabriela wants to make at least $$82$ this week, we can turn this into an inequality. Amount earned this week $\geq $82$ Subscriptions sold $\times$ Price per subscription $+$ Weekly bonus $\geq $82$ We are solving for the number of subscriptions sold, so let subscriptions sold be represented by the variable $x$ We can now plug in: $x \cdot $7 + $21 \geq $82$ $ x \cdot $7 \geq $82 - $21 $ $ x \cdot $7 \geq $61 $ $x \geq \dfrac{61}{7} \approx 8.71$ Since Gabriela cannot sell parts of subscriptions, we round $8.71$ up to $9$ Gabriela must sell at least 9 subscriptions this week.